a, b, c = input().split()
sp = ['zero', 'one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight', 'nine']
summa = ''
prostie = [101,	103,	107,	109,	113,	127,	131,	137,	139,	149,	151,	157,	163,	167,	173,
	179,	181,	191,	193,	197,	199,	211,	223,	227,	229,	233,	239,	241,	251,	257,	263,	269,	271,	277,	281,
	283,	293,	307,	311,	313,	317,	331,	337,	347,	349,	353,	359,	367,	373,	379,	383,	389,	397,	401,	409,
	419,	421,	431,	433,	439,	443,	449,	457,	461,	463,	467,	479,	487,	491,	499,	503,	509,	521,	523,	541,
	547,	557,	563,	569,	571,	577,	587,	593,	599,	601,	607,	613,	617,	619,	631,	641,	643,	647,	653,    659,
        661, 673, 677, 683, 691, 701, 709, 719, 727, 733, 739, 743, 751, 757, 761, 769, 773, 787, 797, 809, 811, 821, 823, 827, 829, 839, 853, 857, 859, 863,   877,
        881, 883, 887, 907, 911, 919, 929, 937, 941, 947, 953, 967, 971, 977, 983 , 991 , 997, 1009]
f = []
for i in range(len(sp)):
    if a == sp[i]:
        summa += str(i)
for j in range(len(sp)):
    if b == sp[j]:
        summa += str(j)
for k in range(len(sp)):
    if c == sp[k]:
        summa += str(k)
summa = int(summa)
for g in range(len(prostie)):
    if (summa - prostie[g]) < 0:
        f.append((summa - prostie[g]) + (summa - prostie[g]) * -2)
    else:
        f.append(summa - prostie[g])
d = int(min(f))
for p in range(len(prostie)):
    if f[p] == d:
        s = prostie[p]
if a not in sp or b not in sp or c not in sp:
    print('Wrong input')
else:
    print(s)